I made this page for my own sim-flying in Wales.
It may be useful for others too, so I put into Internet.- Scenery used is Just Flight VFR Real Sceneries, Vol 3 Wales & South West England, for FSX Steam.

When are photo sceneries good and when bad?

Aerial photos are taken downwards, not forwards.

When we fly and look forwards it works
well for relatively flat objects like gravel, grass, bushes etc.
that tightly follow ground height variations, but not so good for buildings since we recognize them by their walls,
not by their roofs!

Note also that it is when you look down-left from your aircraft
that you come closest to the aerial photo view.

In future, we will probably get faithful 3D represen­tations of all buildings!

These are combo files with free scenery data from many sim developers.
Their documentations are included in /docs directory.
More • References below.

Installation:
- Copy directory /Wales_airfields_bj to FSX/Addon Scenery
(or other directory, for FSX Steam it must be under /FSX ).
- Register scenery: Start FSX - Settings - Scenery_library -
navigate to /Wales_airfields_bj and click OK.
There is a bug in FSX so the window does not disappear.
Bug-fix is to click in any white space.

Tours in Wales - What to see

Tour 2. Zig-zag Snowdonia: Caernarfon - east into Llanberis valley with large Dinorvic quarry,
fly beside Snowdon Mt, with well visible pathways.
Turn left, and then west into Nant Ffrancon valley to Penhryn quarry.
Onto the southern valley with pass Aberglaslyn. Turn right and return to Caernarfon.
It is easy to get lost! NDB 320kHz in Caernarfon can help.

Tour 3. Northern Coast - from RAF Valley to Hawerden/Chester.
Castles in Beaumarais and Conwy. Large quarry Penmaenmawr (circle around it!).
Wind farm 8km out in the sea. Leisure region around Rhyl. ~60NM

Tour 5. Four railways: Aberporth - N along coast, pass wind farms, check Vale of Rheidol Rwy,
and Talallyn Rwy (not in the big valley!), and Ffestiniogg Rwy, large quarry,
then fly to Snowdon top and follow Rwy down, land at Caernarfon. ~105NM.

Tour 6. Around Pembrokeshire: Haverforwest, N to Fishguard harbour, west along coast,
St Davis cathedral, Milford Haven refineries, east to Pembrey.
You will see sandy beaches, tidal flats, lighthouses,...

Aircrafts for VFR flying

Photo sceneries are best seen form a low-speed aircraft
with free view both forward and down left, and from altitude 1000 - 3000 ft.
Hence, avoid jet airliners, jet fighters, DC-3, and also Piper Cub (its wings limit the view).

Airfields and NDB,VOR in Wales - North to South

In FSX original, small airfields have none or very few buildings.
Larger airports are better, e.g. Cardiff.

I have collected airfield addons into one file, see above.
Contributions: Alf Denham has made addons for many small UK airfields, five in Wales.
Terry Shields has a detailed scenery for Cardiff airport.
Plus material from several others.

You can buy large collections of airfields, e.g.
- Just Flights UK airfields or UK2000.
- Sim720's Caernarfon, airphotos + trees and houses, at Steam.

Altitude mismatches can occur when different scenery add-ons are combined.
Here, before adjustment, buildings were not to be seen,
but with my simple fix the only problem left is a "flying" hangar. See Refs.

4. Avoid double installation: FSX old + FSX-Steam. Creates problems, and old FSX is unstable.
Uninstall of FSX clears in Registry, but does not erase files.
Do that manually, and keep what you want.

5. Graphics card activation (Laptops mainly?). Check with Nvidia Geforce that fsx.exe is set to use GPU.
If you check inside FSX for GPU use, it may wrongly show that it is not used, but it is!
Seems to be a GPU-detection bug in FSX-SE. To check for certain:
Go to Nvidia Control panel and activate GPU-icon:

6. Run in Window mode. Better than fullscreen, in my opinion: Alt+Enter swaps.
Use Virtual cockpit.

Wales Map for FSX - How I made it:
I used a free Road map as base map, from mapmoose.com
Then added airport symbols, landmark symbols and flights, in separate image layers.
Software used was: Paint.net - a freeware similar to MS Paint but more advanced.
Javascript for Distance and Heading, developed by me, free to use with other maps!
Zoom: Map image size is W=2070 H=2500, so you can increase webpage size 200% (Ctrl +).

The Sim720 team has made a detailed Caernarfon airport with surroundings(5x4km), sold on Steam.
They have added houses and trees with correct sizes. It is instructive to compare that with pure photo scenery!
One good use of detailed surroundings is when you are training landings.
Similar addons covering large areas are Treescape and VFR Buildings.
Pros are better 3D perception, cons are more synthetic visualization.